Old 8th Mar 2010, 12:20
  #13 (permalink)  
IO540
 
Join Date: Jun 2003
Location: EuroGA
Posts: 13,786
The thing is that if you have a wastegate set to increase the MP, all bets are off as regards high altitude performance.

I also don't think many turbocharged engines make TBO. Even comparing with a turbonormalised engine, the effect of the immediate power drop on a normally aspirated engine as one climbs prob99 has a huge effect on engine longevity, so even if one holds the CHTs etc steady, the maintenance of sea level MP for the next 10 or whatever minutes will still knacker the engine a lot faster than normal aspiration.

My memory may well be imperfect but I don't recall ever meeting a turbo pilot whose engine made the 2000hr TBO without cracked cylinders or some major work.
IO540 is offline